For the past 25 years, HP has been rolling out its HP-UX Unix operating system on a regular basis to support mission-critical operations.

That's going to continue with the company's upcoming update to HP-UX. The release, codenamed "Vigilance" and officially referred to as HP-UX 11i v3 Update 4, will offer improved virtualization capabilities and performance, InternetNews.com has learned.

But the latest enhancements to the venerable operating system will come as it faces the mounting threat from a more recent arrival: Linux.

The open source operating system is growing in both maturity and its share of mission-critical deployments. While HP sells and supports both HP-UX and Linux -- and sees a place for both -- it maintains that Linux doesn't fit the same needs.

In particular, Brian Cox, director of software planning and marketing for Business Critical Systems at HP, told InternetNews.com that he believes HP-UX is still a more mature operating system.

While he said Linux shares some commonalities with Unix, Cox noted that it has taken HP-UX 25 years to get to where it is today. Linux is a little more youthful, at almost 18 years old.

"Linux is just younger, and it's just not as far along in terms of building out the full repertoire of capabilities that enterprise IT is looking for," Cox said. "If you look at any kind of IT deployment where you're having to process million of transactions per second or having to handle queries on data warehouse in the tens of terabytes, it's still really beyond proven capability of Linux."

Yet there's signs that Linux is showing its own large, mission-critical wins.

Leading Linux vendor Red Hat helps to power the New York Stock Exchange and NYSE Euronext family of exchanges, for instance. InternetNews.com reported at the time of NYSE's move to Red Hat Enterprise Linux that the exchange had previously used HP-UX, IBM AIX and SUN Solaris.

Still, when it comes to the current state of competition with Linux, there are places where the newer contender still has its work cut out for it, Cox said.

"It has taken 25 years for HP-UX to get to where it is today, running major stock exchanges, running healthcare operations and 911 systems," he said.

Cox added that Linux still plays an important role for HP, which contributes its own intellectual property to Linux in the form of the AdvFS Unix file system technology.

In fact, Cox noted that HP continues to support multiple operating systems including Unix, Linux, Windows and the more than 30-year-old OpenVMS as well.

"We're still very bullish on Linux," he said. "I don't want to downplay Linux's importance to our customers and to HP. Some things just take time."

Countdown to Vigilance

While HP has emerged as a solid backer of Linux, it's put far longer into its support for Unix over the last 25 years -- a key component of which has been its regular updates to HP-UX.

HP updates the operating system in the spring and fall of each year. The last update was October's HP-UX 11iv3 Update 3, with the previous spring update (Update 2) arriving in April 2008.

That pace will continue with the upcoming Update 4, "Vigilance", which promises a slew of improvements to in-demand features like virtualization.

"In Update 4, you'll be seeing enhancements in virtualization which is a big investment area for us," Cox said. "Everyone can do partitions, where there is a hypervisor that will carve up a physical machine into multiple virtual machines. The challenge is about how flexible it is to move machines around to take advantage of resource demands."

What that has led to, however, is what Cox referred to as "virtual server sprawl."

"You used to be able to physically count how many servers you had but now with virtual servers, it's harder to do a headcount," he said. "Providing tools to find where all the virtual servers are and where all the different applications are and where they go and how many resources are being consumed -- that's today's challenge."

Virtual machine management is something that the broader virtualization market is also tackling with recent management product releases from Red Hat as well as from VMware, Microsoft and Citrix.

Cox also noted that performance improvement in the virtual space will also be addressed in the HP-UX update.

"How a machine operates in a virtual environment places some different workload demands on the server than if you just had one or a few applications on a physical box," he said.

He added that data protection will also get boost, with improvements to high-availability and disaster tolerance.